NITROGEN. 41 



NITROGEN. 



Nitrogen is a permanent gas. It has neither 

 taste, color nor smell, and is destitute of active 

 properties. It is incombustible, and will not 

 support combustion or respiration. Its most im- 

 portant function is to dilute the oxygen of the 

 atmosphere,, which contains 77 per cent, by 

 weight, or 79 per cent, by volume of nitrogen. 



Nitrogen does not enter into direct combina- 

 tion with any elements, excepting oxygen, with 

 which it may be made to unite by subjecting the 

 mixture of the gases to a succession of powerful 

 electric shocks. The union of nitrogen with 

 oxygen in proper proportions produces nitric 

 acid, consisting of one equivalent or 14 parts 

 of the former, with 5 equivalents or 40 parts of 

 the latter. 



Nitric acid in small quantity is produced in 

 the atmosphere during thunderstorms by the 

 same agency, and is absorbed by rains, thus 

 furnishing a limited supply of this element to 

 plants. 



As before stated, 14 parts of nitrogen uniting 

 with 3 parts of hydrogen, form ammonia; this 

 compound, with nitric acid, being the most im- 

 portant source of nitrogen for plants. 



Nitrogen is so essential to the growth of 

 plants, that no matter if every other element 



